Jogai · March 2, 2016 11:39 · Mar 2, 2016
diff --git a/from_memory.md b/from_memory.md
@@ -0,0 +1,45 @@
+Taken from https://github.com/secretGeek/til/blob/master/asp.net_mvc/from_memory.md
+
+# Handy Cache helper method
+
+I love this little thing.
+
+
+
+
+
+    public static T FromMemory<T>(string Key, Func<T> func, double days = 7) where T : class
+    {
+        var value = MemoryCache.Default.Get(Key) as T;
+        if (value == null)
+        {
+            value = func();
+            if (value != null)
+            {
+                MemoryCache.Default.Add(Key, value, DateTime.Now.AddDays(days));
+            }
+        }
+
+        return value;
+    }
+
+
+Then, instead of simply retrieving something from storage, e.g.
+
+
+    var items = LoadSiteMap();
+
+You do this slightly awkward, but fairly clean alternative:
+
+
+    var items = Latest.FromMemory("SiteMap", () => LoadSiteMap());
+
+You do have to tell it the cache_key to use.
+
+You can override the default duration to hold it in memory...
+
+    var items = Latest.FromMemory("SiteMap", () => LoadSiteMap(), 0.1);
+
+And if things go really pear shaped, and it can't infer the types, you might need to specify them, for example here:
+
+    var items = Latest.FromMemory<List<ISitemapItem>>("SiteMap", () => LoadSiteMap(), 0.1);